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255

3:56 pm
May 15, 2017
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Training, Automation Drive Extrusion Reliability

(All photos courtesy of Aquatherm.) When designing the new extrusion plant, the team needed a solution to how best deliver the cooling water for the extrusion process. After some creative design work, it was decided to create a 300-ft.-long tunnel under the facility, specifically for this purpose.

When designing the new extrusion plant, the team needed a solution to how best deliver the cooling water for the extrusion process. After some creative design work, it was decided to create a 300-ft.-long tunnel under the facility, specifically for this purpose. All photos courtesy of Aquatherm.

German-based Aquatherm provides reliable, sustainable pipe production as a result of advanced technology, automation, and in-house design and innovation.

By Michelle Segrest, Contributing Editor

As one of the first three companies in the European market to manufacture under-floor heating systems, German-based Aquatherm, headquartered in Attendorn, has come a long way since the company was founded 44 years ago. It now leverages state-of-the-art automation and innovative energy-saving systems to drive its reliability and sustainability programs.

“Until a few years ago, maintenance employees needed to localize and correct a fault indication directly at a machine if a system error occurred,” explained Aquatherm’s Maik Rosenberg, the company’s global co-managing director. “Power converters and frequency converters could only be parameterized manually or adjusted by potentiometers. Now, we can access the central control from various places within the company. If needed, we can access every single drive of an extrusion line.”

Maintenance staff members can correct faults using smartphones and also receive repair orders directly from a tablet. They use the handheld technology to recall all the information needed for order fulfillment in a central folder, and then take advantage of the ability to choose required materials from its digitized stock inventory.

“It is possible to operate all our machines online through our production-activity control system,” Rosenberg said. “The system enables us to monitor the energy consumption of all the machines and their components.”

The use of automation has enabled Aquatherm to establish itself as one of the world’s leading manufacturers of plastic piping systems for heating, cooling, domestic water, industrial, and sanitary applications. The company was founded in 1973 by Gerhard Rosenberg for the development, production, and installation of warm-water, under-floor heating.

In 1980, the company developed the plastic pipe system Fusiotherm, which is made of polypropylene-random (PP-R) for sanitary equipment and heating installations. This innovation has been the foundation of Aquatherm’s continuous growth. The company has developed into a global business that is represented in 75 countries and is a market leader in many sectors and application fields.

Aquatherm employs almost 600 employees within the group of companies. In 2016, it manufactured more than 40,000 km of pipe and 50-million molded/fabricated components out of 18,000 ton of raw materials.

In April 2017, Aquatherm opened a state-of-the-art 160,000-sq.-ft. facility in Attendorn that features 19 extrusion lines. The building has been designed and constructed to offer space for a total of 32 production lines, underscoring the company’s commitment to future growth.

Aquatherm North America (Aquatherm NA) was established roughly 10 years ago as a sales, marketing, and support partner and operated independently until late 2015 when Aquatherm Worldwide assumed control of the North American companies Aquatherm LP (U.S.) and Aquatherm Corp. (Canada). North American operations are based in Lindon, UT, and feature a new 82,000-sq.-ft. facility that opened in April 2017. All corporate departments are housed in this facility, along with a cutting-edge Design and Fabrication Services department and quality-assurance laboratory.

This is a portion of the process-cooling system for Aquatherm’s new extrusion lines. Aquatherm pumps more than 121-million gal. each year from the Bigge River at temperatures from 50 F to 57 F. By German law, the water returned to the river can be no more than 73.4 F. The firm has three water loops running through heat exchangers—process cooling, electric-motor cooling (the largest motor is 800 kW), and heat recovery for space heating and domestic hot water.

This is a portion of the process-cooling system for Aquatherm’s new extrusion lines. Aquatherm pumps more than 121-million gal. each year from the Bigge River at temperatures from 50 F to 57 F. By German law, the water returned to the river can be no more than 73.4 F. The firm has three water loops running through heat exchangers—process cooling, electric-motor cooling (the largest motor is 800 kW), and heat recovery for space heating and domestic hot water.

Maintenance best practices

Aquatherm’s maintenance team includes 40 specialized workers—metal workers, electricians, and machine fitters. Most are maintenance foremen and technicians. Consistent and regular training is the key to keeping the team up to date with the latest technologies.

“Our maintenance workers are trained regularly, both in-house and externally,” Rosenberg said. “We empower them to perform their tasks as efficiently and quickly as possible.

The operations and maintenance teams work closely together. Short distances between the different departments make it easy to react quickly to challenges and encourage cooperation and information exchange between team members. Aquatherm is committed to keeping most of the maintenance of its equipment in house. “It is part of our company culture to do as much of our maintenance in house as possible with our highly qualified staff,” Rosenberg said. “We have a staff design team, which uses CAD to design our extrusion and injection-moulding tools. The tools are then manufactured in our tool shop. For us there is great value in using our own experienced staff to design special tools. This allows us to be highly flexible. We can react to new requirements quickly and appropriately while ensuring we preserve our high standards.”

Automation and advanced technology continues to play a key role.

“One good example of how our maintenance team made a difference for our production department and helped us to save costs is the installation of an additional measuring device at the beginning of our extrusion lines,” Rosenberg explained. “The device measures the pipe diameter and compares the pipe’s actual value with standard values. Previously, we only had a measuring device at the end of the production lines. With the new device installed at the beginning of the line, we can react immediately to variations and adjust the machine settings, as necessary. This is a simple but smart solution that has helped us reduce machine setup times and increase product quality.”

Aquatherm’s new extrusion lines operate three shifts a day, and ran for more than 340 days in 2016. Aquatherm engineers designed everything in the plant itself, including the control systems. The firm designs, builds, and automates their production lines, rather than purchasing complete lines, which may not be optimized for their product lines. Because they had to maintain production, it took 10 months to move the lines from the old building into the new building.

Aquatherm’s new extrusion lines operate three shifts a day, and ran for more than 340 days in 2016. Aquatherm engineers designed everything in the plant itself, including the control systems. The firm designs, builds, and automates their production lines, rather than purchasing complete lines, which may not be optimized for their product lines. Because they had to maintain production, it took 10 months to move the lines from the old building into the new building.

Building for growth

Planning and development of the new extrusion production facility was done in-house with a team of experts. From the initial planning phase, all participating departments were involved—extrusion, building-technology, electrical, metal-working, and technical-purchasing departments, as well as plant and company management.

“The idea behind staffing it was to have a cross-functional team combining the experience of all departments and to implement missed opportunities of the past in the new building,” Rosenberg said. “The ideal pipe production was planned using all the technical and organizational input of the entire team.”

All 19 extrusion lines now are located on the ground floor of the building. The material supplies, as well as auxiliary and packaging materials, are provided on the upper floor. The material supply is almost fully automated, Rosenberg said. The raw materials are transported directly from the supply silos, which are located outside the building, using seven coupled stations that move the materials through the ducts to the machines.

“All cooling, power, water, and compressed air is supplied directly to the machines through a central supply channel integrated in the floor,” Rosenberg explained. “This allows the respective areas to be clearly separated in a structured way, enabling the focus to be on respective core competencies of the involved teams. All process and building controls (material supply, cooling systems, fresh air, light, and safety engineering) were programmed and managed in house.”

The new 160,000-sq.-ft. Aquatherm manufacturing facility features 19 extrusion lines, has space for a total of 32 lines, and is all concrete to comply with German fire codes that deal with plastics fabrication. In 2016, the company manufactured more than 40,000 km of pipe and 50-million molded/fabricated components out of 18,000 ton of raw materials.

The new 160,000-sq.-ft. Aquatherm manufacturing facility features 19 extrusion lines, has space for a total of 32 lines, and is all concrete to comply with German fire codes that deal with plastics fabrication. In 2016, the company manufactured more than 40,000 km of pipe and 50-million molded/fabricated components out of 18,000 ton of raw materials.

Sustainability

Sustainability has been a core value of the company from the time it was founded more than four decades ago, according to Barry Campbell, vice-president of marketing, Aquatherm North America.

“We believe sustainability is a vital component in a company’s success,” Campbell explained. “That is why we have certified our energy-management system according to DIN EN ISO 50001 and our environmental-management system according to DIN EN ISO 14001. It is also why we are the only piping system in North America that can contribute directly to LEED v4 points. We consistently are working to reduce our consumption of energy, water, and resources, as well as lower the amount of our waste and emissions. For example, in 2015, we saved more than 42 tons of carbon dioxide. We also reduced the consumption of raw materials by more than 288 tons by reusing plastic materials in our production processes.”

Energy savings play into the company’s sustainability picture. “We use the hot water, hot air, and waste heat generated during production processes to heat our state-of-the-art extrusion building, as well as another building,” Rosenberg said. “The total heated area is approximately 15,500 square meters. The system that we have in place is so efficient, we only need additional heating for approximately 10 days a year when production is down during the Christmas holidays.”

The company also started a program to replace the lamps in all of its production and warehouse buildings with LEDs.  “To save energy, we also have installed movement-sensitive lighting in the technical basement of our new extrusion building,” Rosenberg added.

Automation triggers continuous improvement

With constant changes in technology, automation continues to be a crucial element in every one of Aquatherm’s processes.

“Automation gains more and more importance, especially with regard to quality control,” Rosenberg said. “One example is the in-line measurement of pipe-wall thickness. Monitoring data is sent to our control center and displayed as graphics on computer monitors. In the event of an error, a message is sent to the shift supervisor and an alarm warns the lead operator. This allows us to constantly minimize reaction time, helping us to guarantee product quality.”

Additionally, Aquatherm controls many physical parameters—including temperature, speed, and melting behavior—in real time.

“Soon, we will be equipping our maintenance teams with tablets, which will enable them to perform remote maintenance from home on weekends when they are on call,” continued Rosenberg.

To help ensure continuous improvement, the company enhances its automation and technology with old-school methods that still contribute to overall productivity. “We hold meetings at the end of each shift,” Rosenberg said. “In these meetings, we review the shift, analyze what went well, and discuss any issues that need to be addressed. All information is summarized and written in a hand-over report. All of our manufacturing plants communicate regularly and share best practices and, in the end, it’s a combination of all these things that make us a productive and sustainable company.” MT

Michelle Segrest is president of Navigate Content Inc., and has been a professional journalist for 28 years. She specializes in developing content for the industrial processing industries and has toured manufacturing facilities in 41 cities in six countries on three continents. If your facility has a good operational, reliability, and/or maintenance story to tell, please contact her at michelle@navigatecontent.com.

68

3:36 pm
May 15, 2017
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Put Portable Filter Carts to Work

Portable filter carts play a crucial role in equipment uptime by being able to deliver lubricants at the right cleanliness level and transfer and clean oil while machinery runs. (Source: EngTech Industries Inc.)

Portable filter carts play a crucial role in equipment uptime by being able to deliver lubricants at the right cleanliness level and transfer and clean oil while machinery runs. (Source: EngTech Industries Inc.)

Don’t set up a lube program without one or more of these multi-taskers.

By Ken Bannister, MEch Eng (UK)CMRP, MLE, Contributing Editor

The ability to control contamination is an important aspect of any lubrication-management program, especially where lubricant cleanliness is concerned. A constant supply of clean oil is essential to lubricant life and, more important, bearing life.

One of the most efficient and practical tools available to ensure lubricant cleanliness is the portable filter cart. In a typical industrial environment, portable filter carts are used to transfer and clean all types of lube, gear, and hydraulic oils. The carts’ three principal applications in a lubrication-management program are:

• transferring oil from its original container into a machine reservoir
• pre-filtering and cleanup of virgin stock (new) oil in preparation for machine use
• reconditioning and cleanup of oil currently in service.

In addition, use of specialized filters on the outlet side can extract any free and emulsified water present in the oil.

Functionality

The primary function of any filter cart is to filter fluids. A typical cart design will employ a two-stage filtration approach in which a gear pump is connected to both filters. The inlet, or suction, side is the first-stage, low-pressure side (approximately 5 psid) designed to capture larger contaminant particles exceeding 150 microns in size.

Oil is pumped through the inlet filter to the second-stage, high-pressure (approximately 25 psid) outlet (or delivery side) filter designed to capture much smaller particulate matter that can be filtered to less than 5 microns in size, depending on the filter rating used.

Listen to the latest in a series of monthly lubrication-related podcasts with Ken Bannister. The May podcast focuses on the selection of and best practices regarding portable filter carts.

How clean should your oil be?

Oil cleanliness is universally measured using the ISO 4406 cleanliness code rating system. This is a standard that quantifies the number of contaminant particles, 4, 6, and 14 micron in size, that are present in a 1-ml lubricant sample and compares them with a particle concentration range, resulting in an ISO-range number value.

For example, a 19/17/14 lubricant sample value (typical of new oil) translates to the presence of 2,500 to 5,000 particles >4 microns in size, 640 to 1,300 particles >6 microns in size, and 80 to 160 particles >14 microns in size present in the oil sample.

Screen Shot 2017-05-15 at 10.29.48 AM

When new or virgin stock oil is received from the supplier, many sites believe they are receiving a “ready-to-use” product. This is not always the case, as depicted in the table. New oil is typically received around a 19/17/14 ISO cleanliness level that may only be suitable for non-critical gear systems. All other applications will require the oil to be cleaned and polished by passing it through a filtration system prior to use in service.

The table also notes that “In service” oil dirtier than 19/17/14 is unsuitable for any lubrication or hydraulic system. Such oil will require replacement or cleanup using a kidney loop set-up with a portable filter cart.

The number of passes through the filter cart to achieve the appropriate cleanliness level will depend on the “start” and “finish” cleanliness level and the filter types and rating in use. Oil analysis will be required to establish cleanliness levels. Choosing a suitable combination of pump and filter size/type will require consultation with the filter-cart manufacturer who will need to understand your working environment and type/viscosity of oil(s) you use.

The rate of cleanup (speed) will depend on the reservoir size, pump flow rate, and the cleanliness-rating delta. What can be measured immediately is the time to perform one complete filter pass through the cart, as calculated using the following formula:

(Reservoir size x 7)/filter-cart flow rate =  time for a single-pass filtration

Example: 60 gal. x 7/10 gpm = 42 min. for a single-pass filtration (1 x filtration of reservoir capacity)

If the plant’s lubricants are consolidated and cleanliness levels are known, a matrix can be developed to determine how many passes are required to filter to an acceptable cleanliness level.

Best practices

As in all other facets of maintenance, there are a number of best practices associated with the use of portable filter carts:

• Work with the filter cart supplier to determine the right pump and filter choice for your plant requirements.

• To eliminate cross contamination of lubricants, each filter cart must be dedicated to a single lubricant use for transfer and cleaning of lubricants. Pilot the filter cart program with the most-critical and/or most-utilized plant-lubricant type.

• Always clean the unit after each successful transfer operation, paying particular attention to the wand ends and open drip tray under the filters and pump area. Open oil is a dirt attractant and can be transferred unwittingly if the cart and its components are not kept scrupulously clean.

• Unless specified, most filter carts are sold with open-end transfer wands fitted to the delivery and suction hose ends designed to slide easily into the reservoir openings of the donor and recipient reservoirs. In a program designed to filter contaminants from the oil, this type of delivery fitting can allow moisture and dirt contamination into the respective reservoirs during the transfer process. To combat this, and ensure a contamination-free transfer process, fit the filter cart delivery/return hose ends and reservoir fill/drain ports with quick-lock-style couplings. As the reservoir is now airtight, it will also require a quality desiccant-style breather to be fitted and, in the case of larger capacity reservoir, a closed-loop expansion tank.

• Specify kink-resistant flexible suction and delivery hose to prevent pump cavitation. Clear hoses allow a visual reference of the oil flowing through the lines.

• The cart’s electric motor will require access to electricity. Ensure that an electrical outlet is within easy reach of the unit’s electrical cord. If the cord is short in length, consider mounting a retractable electrical cord caddy on the unit with enough cord length to reach the nearest electrical outlet.

• Paint a lined box similar to a lay-down area as close as possible to the oil reservoir that’s to be serviced. This allows a cart to be positioned and used quickly without obstruction, and within reach of its hose and wand assemblies.

• Place the cart on a preventive-maintenance (PM) check program prior to every use to ensure the unit’s filters don’t go into bypass mode from being too dirty.  MT

Contributing editor Ken Bannister is co-author, with Heinz Bloch, of the book Practical Lubrication for Industrial Facilities, 3rd Edition (The Fairmont Press, Lilburn, GA). As managing partner and principal consultant for Engtech Industries Inc. (Innerkip, Ontario), he specializes in the implementation of lubrication-effectiveness reviews to ISO 55001standards, asset-management systems, and training. Contact him at kbannister@engtechindustries.com, or telephone 519-469-9173.


learnmore2“Lubricant Fundamentals: Lubricant Life-Cycle Management”

“Offline Filtration: Key to Establishing and Maintaining Oil Cleanliness”

513

6:23 pm
April 13, 2017
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Maintenance Efficiency: Understand It To Drive It

Various factors and measurements affect an organization’s ability to improve workforce efficiencies.

Worker of oil and gas refinery

By Al Poling, RAM Analytics LLC

It’s a given: Maintenance is the largest fixed cost in manufacturing. Maintenance-workforce efficiency has a profound effect on that cost and, in turn, overall business performance. Can that efficiency be improved and, if so, how?

The common metric used to measure this efficiency is wrench time. Research on wrench time has revealed maintenance workforce efficiencies ranging from 18% to 74%. In other words, inefficient maintenance operations will spend exponentially more on maintenance labor than the most efficient operations to complete the same amount of work.

To illustrate the significant financial impact of maintenance workforce efficiency, a highly efficient operation with 74% wrench time spends $100 million/yr. on maintenance labor. A highly inefficient maintenance operation would spend more than four times that amount (or more than $400 million annually) to complete the same volume of work. Translation: The inefficient maintenance operation would waste $300 million a year due to inefficiency.

Critical factors

Numerous factors influence effective use of maintenance labor resources. At the top of any list, however, is a well-defined maintenance-work process. This type of process describes, in detail, each step of maintenance work from identification through execution and closure. Despite claims to the contrary, there is effectively only one universally used maintenance workflow. The five major components are identification, planning, scheduling, execution, and closure:

Identification is the timely pinpointing and prioritization of maintenance work. These activities are performed by equipment operators who use a well-defined work-prioritization matrix or by maintenance coordinators who base priorities on business and related needs.

Planning is formal organization of the work to be done, including scope assessment and identification and procurement of the labor and materials required to complete the job.

Scheduling includes setting the optimum time period in which to complete the planned work. It takes into account the overall resources required at the site and attempts to level the resource load to use normally available maintenance resources.

Execution is the actual hands-on work performed by skilled maintenance craft personnel. This includes company personnel and contract maintenance workers.

Closure involves capturing work history, including critical information on failure modes used to facilitate reliability analysis.

Failure to have or follow a well-defined maintenance-work process results in chaos and, therefore, grossly inefficient resource utilization.

Tools and prep

The next factor that influences maintenance-labor efficiency is the availability of tools and materials required to complete the assigned work. Without that availability, work can’t be completed in a timely manner.

Wrench-time studies consistently reveal that traveling for tools and materials is the most common barrier to maintenance-workforce productivity. If highly skilled (and costly) maintenance-craft personnel have to spend time retrieving tools and materials, it will take significantly longer to complete the work, including possibly delaying completion. It’s troubling why so many organizations depend on highly skilled maintenance resources to perform such mundane work (material and tool transport) rather than assigning those tasks to less costly storeroom and/or delivery personnel.

Next in line as a detrimental impact on maintenance-workforce efficiency is the interface with operations. Equipment must be prepared in advance of maintenance work. Examples include equipment decontamination, lockout/tagout, and work permitting. If these types of tasks aren’t performed in a timely manner, wrench time will suffer. Paying highly skilled maintenance workers to stand around while operators perform such work—that should have been done in advance—is absurd. Yet, as wrench-time studies show, this is a common occurrence in today’s plants.

The culture effect

Empirical evidence suggests that particular work environments, or cultures, are more prone to maintenance workforce inefficiency. At the top of this list is an environment in which unreliable equipment reigns. In this type of reactive environment, it is virtually impossible to achieve high levels of maintenance-workforce efficiency. Unplanned failures, by their very nature, don’t facilitate planning and scheduling, leading to extremely inefficient and expensive reactive corrective work. As if this weren’t bad enough, it is invariably the value of lost production and subsequent lost profit that causes the greatest economic harm to the site and business. Sadly, these costs are often overlooked.

The next environment most prone to maintenance workforce inefficiency is one where maintenance labor costs are low. Southeast Asia, for example, experiences severe inefficiencies—often at appalling levels. In those regions, it’s not unusual to find human labor being utilized instead of equipment. For example, you might find large numbers of maintenance workers with shovels doing the work that a single bulldozer could complete in short order. Sometimes, though, this is by design, i.e., to create more jobs to support a growing middle class. Nonetheless, while it’s an expensive way to operate, the costs can be more easily absorbed due to exponentially lower-skilled maintenance-craft wages.

Surprisingly, highly reliable operations represent yet another, although not necessarily obvious, area where maintenance inefficiencies can be found. In such environments, the business is typically enjoying very high profit margins as a result of achieving maximum production with existing assets.

Of course, it’s human nature for people to focus on what’s important and overlook anything that’s deemed less so. Thus, in a highly reliable production environment, as profits rise, maintenance-cost management can take on a lower sense of urgency. In extreme cases, the inherent inefficiency can lead to anywhere from tens to hundreds of millions of dollars in unnecessary maintenance expense. Interestingly, this situation may also occur in less-reliable operations when the market is tight and profits are high. (It’s not uncommon for managers to remove any maintenance cost controls as long as sales demands are satisfied.)

In both of those scenarios, however, maintenance inefficiency will only be tolerated as long as profit objectives are being met. As soon as market conditions change, pressure will once again be applied to maintenance cost and, subsequently, to maintenance-workforce efficiency. The reaction to this often-sudden change can be quite ugly as arbitrary rules with the potential for unintended consequences, e.g., discontinuing proactive maintenance as a way to reduce maintenance labor costs, are put in place.

Effective measuring

In an ideal production environment, skilled maintenance resources are used efficiently and effectively. As the father of statistical process control W. Edwards Deming advised, “You can’t manage what you don’t measure.”

To ensure that maintenance resources are being efficiently and effectively utilized, they must be measured. Although not used extensively today, the early 20th century methodology of maintenance-work sampling provides an effective means to measure wrench time. (Despite exaggerated claims by some that this sampling is akin to Frederick Taylor’s infamous time and motion studies of the late 19th century, it is not.)

Maintenance-work sampling is simply a statistical tool that, when used effectively, can measure maintenance-workforce productivity. Identification and elimination of barriers to productivity can significantly increase the value-added contribution of existing maintenance resources. Work sampling is the process of capturing and analyzing a statistically valid number of random observations to determine the amount of time, on average, that workers spend in various activities throughout their normal workdays. Non-value-added activities are then targeted for reduction and/or elimination using root-cause analysis.

The maintenance-work sampling approach is based on the proven theory that the percentage of observations made of workers doing a particular activity is a reliable measure of the percentage of total time actually spent by the same workers on the activity. The accuracy of this technique is, naturally, dependent upon the number of observations. To achieve a 95% confidence level in the results, approximately 3,000 observations must be made and recorded. While this might seem excessive, a single trained observer can collect that number of observations during a week of single 8- or 10-hr.maintenance work shifts.

Keep in mind that maintenance-work sampling makes it possible to measure utilization of work groups and the overall maintenance workforce. Key opportunities that warrant attention can be isolated and examined. A good example is that of travel time involved in obtaining requisite maintenance tools and materials and delivering them to where they will be used. That time can be accurately measured and a cost assigned simply by taking the number of total hours consumed by the activity and multiplying by the hourly rate.

Additionally, with maintenance-work sampling, unique factors that affect maintenance wrench time can often be identified. For instance, if inadequate means of communication exist between a work group and the supervisor, valuable time can be wasted tracking each other down. Radios or mobile phones, can solve this problem.

Screen Shot 2017-04-13 at 1.06.43 PM

Screen Shot 2017-04-13 at 1.07.01 PM

The accompanying charts (Figs. 1 and 2) are based on a real-world case study where work sampling was leveraged to identify and eliminate maintenance-workforce inefficiencies. Figure 1 depicts a decline in non-value-added activities, while Fig. 2 depicts an increase in value-added activities.

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As these charts show, initial measurement of the site’s maintenance-workforce wrench-time revealed a mere 28% value-added work (wrench time). Through the systematic reduction and/or elimination of non-value-added activities over the course of three years, the wrench time rose to 74%. What really matters here, however, is the recovery of the value of time that was being wasted, as shown in Table I. (Efficiency gains can also be measured in terms of full-time-equivalents, as shown in Table II.)

As part of its development and publication of standard reliability and maintenance metrics, the Society for Maintenance and Reliability Professionals (SMRP, Atlanta, smrp.org) published its work-management metric, 5.6.1 Wrench Time, in 2009. The stated objective of this metric is “to identify opportunities to increase productivity by qualifying and quantifying the activities of maintenance craft workers.”

The Society also published the SMRP Guide to Maintenance Work Sampling, in 2012. As one of three co-authors, I can state definitively that the intent of this publication was to educate younger reliability and maintenance professionals who had not been exposed to maintenance-work sampling. Although adoption has been slow, several companies are beginning to include this sampling methodology as a valued component in their reliability and maintenance tool kits. Ironically, sites are often introduced to maintenance-work sampling by maintenance contractors who want to demonstrate the efficiency and effectiveness of the skilled maintenance-craft personnel they provide.

(Editor’s note: SMRP’s Guide to Maintenance Work Sampling is a simple “how to” document that includes statistical tables designed to help users understand the correlation of the confidence level associated with a number of observations. The guide can be purchased for a small fee at SMRP.org. The co-authors donated their time to the development and publication of this document and receive no royalties from its sale.)

Last words

While it might be enticing to simply reduce the number of skilled maintenance craft workers on site as wrench time increases, a more prudent path may be to redeploy resources and invest in failure-prevention activities and/or infrastructure.

Increased wrench time may also provide an opportunity to reduce overtime as resources become available and/or to reduce the reliance upon third-party maintenance resources. With today’s critical shortage of skilled maintenance workers, however, displaced workers would likely be able to secure employment elsewhere.

In summary, maintenance wrench time plays a significant role in measuring efficient utilization of skilled maintenance-craft personnel. This valuable metric can be used by any manufacturing operation to ensure that it is realizing the greatest return possible from its investment in human capital. MT

Al Poling, CMRP, has more than 36 years of reliability and maintenance experience in the process industries. He served as technical director for the Society for Maintenance and Reliability Professionals from 2008 to 2010. Contact al.poling@ramanalytics.net.

150

6:03 pm
April 13, 2017
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A Hoarder of Information

When it comes to lubrication, Scott Arrington relies on 34 years of information gathering to ensure he always has the correct answer for his customers.

High-tech equipment helps Arrington and his team provide accurate analysis and improve the reliability of all equipment.

High-tech equipment helps Arrington and his team provide accurate analysis and improve the reliability of all equipment.

By Michelle Segrest, Contributing Editor

Screen Shot 2017-04-13 at 12.24.37 PMScott Arrington is a hoarder—a self-described hoarder of information, that is. The World Wide Web is not big enough to hold all the information upon which he relies. In fact, he has so many manuals, binders, and oil samples, he needs two offices—one to work in, and another to contain all the valuable records, documentation, and research he will never throw away.

Arrington is the Lubricants Technical Manager at G&G Oil Company, Muncie, IN. When a customer calls with a question, he wants to be sure he has the correct answer. “I have abundant resources to make sure we make the correct recommendation the first time and can quickly answer questions from customers. I keep all records of opportunities we have already experienced.” 

As a college student, Arrington worked part-time for the company painting convenience stores, bumper poles, and canopies, and performing maintenance.

“It was a great summer job, and it helped me to get familiar with the business,” Arrington said. “When I graduated from Depauw University (Greencastle, IN) in 1986, I was still looking for a full-time job and the owners of G&G Oil (Bill Gruppe, deceased; Hoyt Neal, retired; and Dale Flannery, retired) were gracious enough to allow me to come work for them in a sales position. They helped me get interviews with a couple major oil companies. I received some nice offers, but when I measured what I really wanted to do and where I really wanted to be, staying here was the best option for myself and my family.”

When making that crucial decision, the opportunity to work with people and with a smaller company were key factors.

“When I graduated from college with my science and physics background, I knew I didn’t want to spend my life in a lab,” he explained. “I was looking around at different options and the owners of G&G Oil offered me a position where I could use my science background to help sell lubricating products while not being tied down to a desk. I was able to get out in the field and see many different and interesting mechanical operations. It was something new every day.”   

Thirty-four years later, Arrington remains loyal to G&G Oil, and now makes significant contributions—in particular with his deep technical knowledge and impact on the lubrication and oil-analysis programs. 

1704fvoice04pMajor responsibilities

It is Arrington’s passion to help customers and prospects solve lubricant-related issues. “From my numerous years of experience and attendance at many major oil companies’ learning seminars, I have been able to absorb quite a bit of knowledge to assist companies and individuals with their lubricating problems,” he said. “I can also assist them with ideas and programs to decrease their total lubrication expenses.”

It is Arrington’s responsibility to answer technical questions from customers and prospects, working directly with key accounts, assisting salespeople with technical sales calls, maintaining current formulas and developing new products, maintaining and updating technical data sheets, approving all raw materials used in formulations, and approving new finished products that G&G distributes for other companies. 

Arrington’s team includes a customer-service manager, a logistics manager, a production manager, and a sales manager. He also works closely with the sales representatives to make sure they are supported with sales opportunities and assistance with current customer questions.

Many of the customer’s questions include inquiries about machine recommendations. “Customers will call in with questions about a certain brand of product for a certain machine,” Arrington explained. “I will delve into the exact specifications of the product they are telling me about and come up with a recommendation of a product we represent—whether it is a G&G Oil-branded product, a Shell Oil-branded product, or from many of the other brands of products we distribute. I try to take away the aura of the name of the specific brand, and assure them that if you don’t have that exact brand, the machine will not keel over and die. I educate the customer about my recommended product and that their warranty won’t be voided if they use another product brand. The warranty will still be in good standing by using the specification of the product, and not necessarily the brand of that product, in their machinery.”

Screen Shot 2017-04-13 at 12.24.49 PMThe importance of lubrication

Arrington said he lives and breathes with a simple philosophy—“Learn all you can, and don’t be afraid to ask questions.” For him, the importance of good lubrication is simple.

“If you don’t have proper lubrication in your equipment, it won’t run the way it’s designed, which will lead to unscheduled maintenance opportunities,” he explained. “If your machinery doesn’t run, you can’t make products to sell. If you can’t make products to sell, your business will suffer and you possibly won’t be around very long! If you are using improper lubrication practices, your machinery will not run at the optimum level. Your maintenance costs will go up because you will have to replace components more often and you will have more unscheduled downtime. Your total maintenance spend will increase if you are not using the correct lubrication product and applying it at the right time, or monitoring it at the right times to make sure your machinery is running at its optimum level.”

Arrington recommends the following lubrication best practices:

• Follow OEM instructions.

• Develop an oil-analysis program that emphasizes:

• condition of the machinery
• trending how the machinery is functioning
• tracking excessive wear of components
• information about the oil (oxidation, contaminants, additives).

If you don’t have your own in-house oil-analysis laboratory, partner with a reputable and certified independent oil-analysis provider. Even if you have your own lab you should use an independent lab to occasionally check your results.

• Use different testing procedures to ensure customers can fully see the condition of their machinery.

• Use proper sampling equipment and procedures.

“A good oil-analysis program is like having a blood test for a human. It can tell you if you have problems with a vital organ or some other part of your body that you may need to look into to take medicine for or have surgery,” Arrington said. “It’s the same with oil analysis—it tells you if the ‘organ’ in the machine is running properly or if it needs to be examined or replaced because it may have excessive wear or other problems, causing it not to work to its optimum level. A good oil-analysis program allows you to be proactive to schedule maintenance instead of being reactive to a break down.”

scottgraphic

Challenges

One of Arrington’s biggest challenges, he said, is developing and producing formulas for new products that G&G Oil can offer to its customers. 

“It’s challenging because of the many different obstacles you’re trying to overcome, especially in the metal-working and metal-removal fluids field. You’re trying to formulate a product for the customer that will have a long life span for the fluid, a good clean finish for the part, and will provide long tool life,” Arrington explained.

There are several different types of additives that can be used, depending on what kind of metal is being manipulated or type of operation being performed. “You have to use the correct balance of those additives to give you an optimum performing product,” he said. “I rely heavily on my additive manufacturers to give me guidance. When I have special projects, I consult with them. I design a product in the lab and then collaborate with my suppliers to get their opinion on whether they think it will work or not.  Fortunately they agree with me most of the time! The formulating depends a lot on what the application is. You have a pool of additives and base oils that you know about. It’s just trying to blend them together correctly to give you the best-performing product for the customer.”

Finding inspiration

Learning and then hoarding information provides constant inspiration for Arrington. As an example, he points to the adage, “Give a man a fish and feed him for a day. Teach a man to fish, and feed him for life.” It is advice he implements in his own work, every day.

Arrington has been married to Stephanie for 20 years and has two teen-aged daughters, MiMi and Ellie. He gives similar advice to his children.

“I’m sure they get tired of it,” he said. “I try to give them advice of the failures I have had in the past—no matter how big or how small—and remind them how important it is to learn from them. I also try to get them to look at the big picture. I want them to see the repercussions of their actions. It may seem like a small thing, but it could be a big thing down the road. I try to be a great representative of myself and my family and my company. My children are growing up in a different time with different challenges and problems, but we all need to learn from history and our mistakes.” MT

Michelle Segrest is a professional journalist and specializes in the industrial processing industries. If you know of a maintenance and/or reliability expert who is making a difference at their facility, send her an email at michelle@navigatecontent.com.

330

4:15 pm
April 13, 2017
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Reliability Changes Lives

Using skilled technicians and advanced technology, Eli Lilly and Company creates life-saving medicines and devices worldwide.

By Michelle Segrest, Contributing Editor

Throughout the halls of the Indianapolis Eli Lilly and Company facility, the corporation's brand is proudly displayed. All photos courtesy of Eli Lilly and Company.

Throughout the halls of the Indianapolis Eli Lilly and Company facility, the corporation’s brand is proudly displayed. All photos courtesy of Eli Lilly and Company.

At Eli Lilly, the motivation to improve production reliability is not just something that is tracked on graphs and charts for upper management to review. In fact, for maintenance and reliability engineer Carrie Krodel, it’s personal.

Krodel, who is responsible for maintenance strategies at the Eli Lilly Indianapolis facility’s division that handles Parenteral Device Assembly and Packaging (PDAP), has a family member who uses the company’s insulin. “I come to work every day to save his life,” she said. “Each and every one of us plays a part with reliability. Whether it’s the mechanics or the operators keeping the line running, the material movers supplying the lines with the products, or the people making the crucial quality checks, everyone is a part of it. And we all know that the work we are doing is changing lives.”

The Indianapolis site covers millions of square feet with nearly 600,000 assets that must be maintained. According to Rendela Wenzel, Eli Lilly’s global plant engineering, maintenance, and reliability champion, the company produces the medicine as well as the packaging for insulin pens, cancer treatments, and many other products and devices.

For the entire Eli Lilly team—which includes a group of about 80 engineers at the Indianapolis site—the responsibility is crucial. “If we mess up, someone gets hurt,” Wenzel said. “This is a big responsibility.”

However, it’s the human element of this responsibility that inspires an exceptional level of quality.

Team, tools, training

Screen Shot 2017-04-13 at 11.03.07 AMWayne Overbey, P.E., is the manager of the Maintenance-Manufacturing Engineering Services department. He said his team of seven maintenance technicians uses three primary technologies every day to keep the machines running—vibration analysis, oil analysis, and infrared technology. With a focus on condition-based monitoring, each team member has an area of responsibility to collect and analyze vibration data. In addition to the vibration data collector, each team member carries a small infrared camera to make heat-signature images used to diagnose and troubleshoot rotating-equipment problems.

The team also uses a digital microscope that can zoom to 3500X magnification. This helps them look closely at a bearing race, cage, and rolling elements and see what caused a failure, whether structural, corrosion-based, or failed lubrication. In addition, the group has an oil laboratory that can analyze oil and grease. 

The team performs more than 7,000 measurements on more than 4,000 rotating/reciprocating machines and performs vibration analysis on those machines monthly, Wenzel stated. The level of qualified individuals is high. “Anything that is process related, we have the equipment to look at it and analyze it,” she said. “We have people with ISO 18436-2 Cat 2 and Cat 3 verifications and even one expert with an ISO18436-2 Cat 4 certification, and there are fewer than 100 people globally with that level of certification. These guys are experienced, high-level certified professionals.”

The maintenance team increased its level of performance more than five years ago when it made the strategic decision to outsource the facilities (buildings and grounds) portion of maintenance. With about 220 maintenance professionals companywide at the Indianapolis facility, this allowed the team to focus more on production and analysis rather than the facilities, Overbey said.

The team has sophisticated data-collection routes set up as PMs and also focuses heavily on maintenance training.

“We have a difficult time finding people interested in maintenance,” Overbey said. “We have a strategic program to train people that takes 18 months to 2 years. When I was growing up, being an electrician or mechanic was a fine career, but now the attitude is that you have to have a college degree to be successful. Most of our crafts people here make more than the average liberal-arts major. As we cycle out the baby boomer work force, we need to find new talent and close the gap.”

Wenzel agreed that finding qualified crafts people has been a focus that has helped Eli Lilly in its drive for reliability.

“Wayne saw the need and developed an excellent program,” she said. “Management is supportive. He is training them and then sending them to get experience while they are going to school.”

The program is responsible for hiring 24 trainees, to date, and has been able to place 18 of them in full-time positions within Lilly maintenance groups. The remaining six trainees are still in the initial stage of the program. The training also uses basic maintenance programs provided by Motion Industries and Armstrong. Last year, there were more than 30 well-attended training classes focused on equipment used at Lilly. The company wants the training to be relevant to what the maintenance technicians perform on a daily basis.

“The whole condition-based platform makes us unique,” Wenzel said. “We have all the failure-analysis competencies. It’s a one-stop shop. We provide two-to-three day courses on condition-based technologies for crafts and engineers. The whole understanding, as far as what maintenance and reliability can do, is to increase wrench time and uptime. We are all seeing an uptake in technology.”

The Indianapolis Eli Lilly facility has more than 600,000 assets that must be maintained by its experienced engineering-services team.

The Indianapolis Eli Lilly facility has more than 600,000 assets that must be maintained by its experienced engineering-services team.

Best practices

Overbey stated that his main responsibility is to help the various site-maintenance groups improve uptime by using diagnostic tools to identify root causes of lingering problems. With a focus on training paying dividends, he said the high-quality people are what make the condition-based monitoring team successful.

The team works with the site-maintenance groups to reduce unexpected failures, so increased time can be focused on preventive maintenance. “We look at our asset-replacement value as a function of our total maintenance scheme,” Wenzel said. “We look at recapitalization and make sure we are reinvesting in our facility. We keep track of where we are with proactive maintenance. Those numbers are tracked facility to facility and then rolled into a global metric.”

Vibration analysis and using infrared technology has become a central part of the department’s reliability efforts.

“These guys have taken responsibility for the failure-analysis lab and taken it on as an added-value service,” Wenzel said. “For example, if there is a failed bearing, they take it out, cut it up, and provide a report that goes back to management. If we make a call that a piece of equipment has increased vibration levels and is on the path to failure, based on the vibration data collected, getting those bearings goes a long way in getting site buy-in when the actual bearing problem can be visually observed. Most individuals are skeptical when shown the vibration waveform (squiggly lines), seeing the bearing with the anomaly is the true test of obtaining their buy in.”

“We can compete with anyone in terms of oil analysis,” Wenzel added. “We can identify particles and have switched to synthetics. For example, when oil gets dirty, it becomes acidic. Something slightly acidic can be more harmful than something that is highly acidic because it will just continue to eat away at the material and cause significant damage before you can stop it. Something slightly acidic can really tear up bearings. The FluidScan 1100 can detect that.”

Screen Shot 2017-04-13 at 11.03.19 AM

More than 80% of the oil samples are now handled internally, Wenzel said. “As we are selling all of these capabilities to the PdM team around the world, we are starting to look at some of the potential issues at other facilities to provide extra analysis with this condition-based maintenance group,” she said. “We are sharing good ideas and processes across facilities. We now have a maintenance and reliability community.”

Eli Lilly employs Good Manufacturing Practices (GMP) and the use of many chemicals requires a high level of cleanliness that is checked daily and regulated by government bodies.

Changeovers can often take weeks. “We check everything,” Wenzel said. “There is very involved and stringent criteria for how we clean a building. Regulations are a challenge, but they keep you on your toes. You don’t even notice it anymore because it becomes a part of what you do. It doesn’t faze the day-to-day thinking.”

The precision and accuracy of the facility's manufacturing equipment contributes to its product excellence.

The precision and accuracy of the facility’s manufacturing equipment contributes to its product excellence.

Operational excellence

Eli Lilly works with cross-functional teams in which maintenance, engineering, and operations are working on the overall process. Operations manager Jason Miller is responsible for running the process. Maintenance corrects the issues and performs preventive maintenance to get ahead of equipment failures and prevent unplanned downtime.

“Anytime we have an equipment failure we evaluate what happened and see what process we can put in place to get ahead of those things,” Miller said. “Line mechanics are on each shift and work with our line operators to understand and troubleshoot issues. We get ahead of issues to ensure [there is] no impact to the quality of our process.

With advanced robotics and a large amount of automation, monitoring performance and quality is key to successful operation and production, Miller stated. “Everything is captured, including downtime and rejects,” he explained. “We identify corrective actions at every morning meeting. We use the data on the line to drive improvement. The line is automated, but if there is a reject every 100 cycles, we need to take action. The robotics never stop. If you see overloads or rejects over time, this tells you about mechanical wear and other issues with the equipment. We drive data-driven decisions for maintenance.”

The preventive maintenance includes lubricating linear slides each month. When vibration is detected, adjustments are made immediately. “The machines tell us what’s going on. We just have to know how to read them,” Miller said. “We have manual and visual quality checks, but the machines also do quality checks. Reliability is critical because when patients are waiting on their medicine, the machines have to run the way they are supposed to run all the time. We have standards, and they have to be precise. This is medicine going into someone’s body. We are the last step of the process. It has to be packaged and labeled correctly, as well.”

Mike Campbell is the maintenance planner and scheduler for PDAP and has developed a system in which all preventive maintenance is performed during scheduled shutdowns.

“We develop a schedule with every piece of equipment and every scheduled PM associated with it,” Campbell said. “One line may have 50 to 60 PM work orders to perform during the week of the scheduled line shutdown. We bring in a lot of resources to do it all at once, typically requiring a day shift and a night shift.”

Advanced production technology is critical to the standard of reliability excellence.

Advanced production technology is critical to the standard of reliability excellence.

Changing lives with reliability

Wenzel said that looking at how each department interacts helps to put all the pieces of the reliability puzzle together. They have even received outside recognition of their practices in Indianapolis. In 2008, The Corporate Lubrication Technical Committee, of which Wenzel is the chair, won the ICML John Battle Award for machinery lubrication.

“It’s not only a cost piece, there is a whole asset-management piece and a whole people piece that we have to look at–not just the numbers, the metrics, the bars and charts–it’s the whole thing that makes a facility tick,” she explained. “Reliability isn’t just my job…it is everyone’s job. Every time I get into my car and turn the key, I expect it to come on. Every time I run that piece of equipment, I want it to perform the same way every time. That, to me, is reliability.”

Overbey said reliability is about being tried and true. “It’s predictable. It’s reliable every day. It’s the whole conglomeration of things that is very complicated, yet very simple. When all is said and done, reliability is a huge advantage for a company. You are only spending money when you need to. But it’s very difficult to get there.”

Wenzel said that consistency is a key to reaching reliability goals. Eli Lilly has global quality standards and good manufacturing practices that are applicable to each of the company’s sites across the world.

“Reliability means the equipment is ready each and every time it runs, and it should perform the same way each time,” Krodel said.

Doug Elam is Level 4 vibration certified, which is a rare level of qualification. He works on Overbey’s team and also tried to define reliability. “Reliability is an all-expansive subject that touches on different types of technology, the goal of which is to improve efficiency in machinery performance,” Elam said. “It requires an intense study of the background functions of the machines.”

Eli Lilly and Company uses robots on an assembly line to carefully package its products.

Eli Lilly and Company uses robots on an assembly line to carefully package its products.

Regardless of the definition, reliability for Eli Lilly always circles back to the human element.

“Patients come through and perhaps are on insulin or a certain pill, or a cancer treatment that has changed their lives,” Wenzel explained. “We listen to them, because it’s not just the medicine that matters, but the packaging and ease of use. It puts what we do in perspective. We take this feedback and incorporate it into our designs. It starts with an end user’s idea and need, goes to design, goes through production, then back to the end user. It’s like a circle of life.”

The research is carefully conducted with the end user always in mind.

“A lot of research is done to make the best fit for each subset of people,” Wenzel continued. “And at the end of the day you have a marketable product that you can be proud of. Being on both sides of the business, you understand why medicine is so costly. But when you find the one niche that helps cancer patients, or the kid who is near death, and then you can be a part of developing this medicine that completely changes his life, it just makes it all worthwhile.”

And yes, it’s personal.

“When you know people who use the products,” Wenzel said, “the work you do becomes a part of you.” MT

Michelle Segrest has been a professional journalist for 27 years. She specializes in the industrial processing industries and has toured manufacturing facilities in 40 cities in six countries on three continents. If your facility has an interesting maintenance and/or reliability story to tell, please contact her at michelle@navigatecontent.com.

314

3:54 pm
April 13, 2017
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Add Electrical Motor Testing to Your PdM Toolkit

This predictive approach offers reliability benefits that time-based maintenance can’t.

Left. A 700-hp, high-voltage stator is being tested after undergoing rewind and the vacuum-pressure-impregnation process.

Left. A 700-hp, high-voltage stator is being tested after undergoing rewind and the vacuum-pressure-impregnation process.

Numerous studies have tried to establish guidelines for creating plant reliability and efficiency. Depending on which research is cited, the bottom line is that between 65% and 75% of all motor failures are mechanical in nature. For that reason, vibration analysis, a cornerstone of any predictive-maintenance (PdM) program, would appear to provide the “biggest bang for the buck” in pinpointing possible problems. Still, while an aggressive vibration-analysis program may accurately predict most mechanical issues, it can’t diagnose the 25% to 35% of motor failures that are due to electrical weaknesses and faults. That’s why electrical testing is so important.

To put it simply, the insulation system within a motor is the unit’s “heart”—and nothing but a series of electrical tests can fully evaluate the health and integrity of that heart. Comprehensive evaluation involves the use of static-testing and dynamic- monitoring technologies. To understand the benefits, it’s important to know why and how motors degrade.

Motor degradation

Various factors, including the initial quality of a motor’s insulation, affect the pace at which it degrades. Since heat is the main enemy of all insulation materials, maintaining a cool, dry environment will increase motor life.

Many things contribute to excessive heat. Typically, the situation is acerbated by a combination of issues that individually wouldn’t create a problem. High ambient temperature, numerous restarts, starting under heavy loads, slight misalignment, some unbalance with the supply voltage, and contamination, all contribute to the heat a motor experiences.

Another issue affecting the life of a motor’s insulation system is starting and stopping. In fact, most plant-floor personnel have, at some point in their careers, heard the old saying that “if you don’t want your motor to fail, don’t start it, and if it’s running, don’t stop it.”

Startup and, to some extent, shutdown of a motor, are generally the most stressful times in the unit’s life. Contactor and breaker “bounce” at startup can generate voltage spiking four or five times greater than the operating voltage. The initial in-rush of AC voltage, pushed by as much as eight or 10 times the nameplate current, “attacks” the insulation and greatly affects the early turns. This startup current causes the motor’s windings to flex or breathe and allows the copper magnet wire to rub and abrade. Because there are only about 1 1/2 mils of insulation baked on the magnet wire, over time it will deteriorate, resulting in arcing during starting and stopping. The appearance of arc is a sign that the insulation is basically at the end of its life. The wearing away of that thin insulation film, in turn, is the beginning of the end for many motors.

Screen Shot 2017-04-13 at 10.37.56 AMOnce arcing has begun, it occurs during every startup, and often during shutdown. It may continue for weeks or even months before it creates a failure. Eventually, though, it will create a carbon path and short out a portion of the windings. These shorted turns will then act as the secondary side of a transformer with voltage and current being induced by the rest of the circuit.

Keep in mind that the ratio of good turns to shorted turns will dictate how severe and how quickly a failure will occur. When shorted turns occur, however, a motor will fail within minutes. Thus, it’s imperative to find weak turn insulation before it becomes a hard-welded fault. If not detected in time, a few weak turns will carry an exponential amount of current that is induced by the transformer effect and quickly burns through the slot-cell liner to ground in the laminations. The result is often a damaged core with a large hole that will always make the rewound motor less efficient and run hotter.

Finding the weak turn insulation and taking the motor out of service before a short occurs provides two valuable benefits:

• Plant-floor personnel are in control of the motor. They decide when a unit is to be removed from service, which minimizes or eliminates unscheduled downtime, emergency repairs, and lost production.

• Since the motor in question still has a good core, a reputable repair shop can rewind it using better materials and parts and tighter balance specifications than when it was first installed.

In practical terms, the site gets a “new” motor back from the shop (not a patched-up one).

The predictive route

A strong PdM strategy can allow personnel to make realistic predictions regarding the useful life expectancy of their motors. The unfortunate fact is that a motor begins (and continues) to weaken and deteriorate from the moment of its very first startup. If it operates in high ambient temperatures, with some misalignment and voltage imbalance, and experiences numerous starts under a heavy load, its life will be short. Given these conditions, a motor that should last, say 20 years, will probably fail in two or three. While correcting some of those issues could prolong the life of the unit, keeping tabs on the health of its insulation could provide greater payback.

Preventive maintenance (PM) efforts are clearly important when it comes to a plant’s motor fleet. For example, in facilities where contamination is an issue, PM routines to reduce its effect on motor life are a must. Whenever possible, however, a PdM strategy that leverages as many proven predictive tools as possible should replace preventive activities. After all, to develop a complete picture of a patient’s health, a physician will typically perform a battery of tests. Your site’s motors deserve similar treatment.

Fortunately, state-of-the-art equipment and methodologies are available to identify early issues before they lead to catastrophic failure(s). Routine testing and trending will detect weaknesses long before they can propagate into an insulation failure. To design this type of PdM program, site personnel need to identify the motors that are most critical to the operation and, in turn, those that are the most problematic. This information will indicate which tests need to be performed and how often.

Many independent testing organizations have detailed specific test parameters, proven to provide sufficient data for the technician to evaluate the immediate health of the insulation. To ensure the capture of accurate data, it’s important that those guidelines be strictly followed. For more information on testing parameters and requirements, refer to IEEE (Institute of Electrical and Electronic Engineers, ieee.org), IEC (International Electrotechnical Commission, iec.ch), EPRI (Electric Power Research Institute, epri.com), and EASA (Electrical Apparatus Service Association, easa.com).

Low-voltage testing, comprised of capacitance, inductance, and resistance tests, provides some useful information, but will not provide early warnings regarding turn insulation. A complete set of tests that will provide the predictive information you need include:

Winding-resistance test: This test will verify that all three phases are similar and all internal connections are tight. It uses a Kelvin bridge and injects about 12 VDC at approximately 7 A into the windings. One poor connection will lead to unbalanced current and uneven heating.

Megohm test: After passing the winding-resistance test, a megohm test is run to measure insulation resistance. The test uses a low-current DC voltage that depends on the nameplate voltage of the motor. A polarization index test (PI), which is an extended megohm test, may provide important information about the insulation if it is old, cracked, or brittle.

High-potential test: If the winding-resistance and megohm tests are acceptable, a high-potential (HiPot), or step-voltage, test may be performed. This test uses increased voltage to create electrical stresses on internal insulation cracks. This can reveal aging or physically damaged insulation. The HiPot test is usually conducted at an elevated level that is at least twice the line voltage plus 1,000 V. EASA and other testing organizations recommend even higher test-voltage levels. The HiPot test may not be appropriate for in-service motors that display low megohms during the megohm test.

Surge test: Once the above tests are satisfactorily completed, a surge test is performed. Since more than 80% of all winding failures begin as a turn-to-turn weakness that can only be detected by a surge test, it is the most important static-testing method. Surge testing applies pulses through a large capacitor at ever-increasing voltage levels and monitors the reaction as the voltage is discharged into a motor’s windings. The purpose is to re-create the spiking that occurs at startup. Doing so requires the capacitor to “fire off” each pulse at a very fast rise time. The intention is to locate weak turn insulation before it has a chance to become a hard-welded fault that leads to a quick failure.

Value proposition

Adding electrical testing of motors to your site’s PdM toolkit puts personnel in the reliability driver’s seat with regard to these units. The value proposition is clear: Routine testing and trending provides sufficient data to make a diagnosis regarding the ability of a motor to remain in operation or to determine if it needs attention. Being in control, i.e., being able to specify when a motor is pulled from service and sent out for repairs, is the essence of predictive maintenance—and an enormous benefit. MT

Information in this article was supplied by Timothy M. Thomas, senior electrical engineer, Hibbs Electromechanical Inc., Madisonville, KY (hibbsinc.com). Email him at TThomas@HibbsInc.com.

307

8:39 pm
April 12, 2017
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Specify the Right Lube-Delivery Line

Fig. 1. Cost should not be a factor in your lubrication-delivery-line choices. While the steel-tubing in this progressive-divider-lubrication system block took more time to install than plastic lines, the additional, but small, up-front cost will pay long-term dividends, especially if leaks or blockages occur.

Fig. 1. Cost should not be a factor in your lubrication-delivery-line choices. While the steel-tubing in this progressive-divider-lubrication system block took more time to install than plastic lines, the additional, but small, up-front cost will pay long-term dividends, especially if leaks or blockages occur.

The wrong lubrication-delivery line can compromise the reliability of your production equipment.

By Ken Bannister, MEch Eng (UK), CMRP, MLE, Contributing Editor

During lubrication-training workshops, I ask participants to name the components that make up a centralized lubrication system. Most will answer in the context of an automated-delivery system by citing the pump, reservoir, metering devices, and pump controller. Rarely do they actually include the lube-delivery lines in their answers.

Lubrication-delivery lines are important and integral components within centralized lubrication systems—be they state-of-the-art automated designs or simple, manual arrangements. Specifying the wrong type can put machinery reliability at risk.

The function of a lubrication-delivery line is straightforward: It must connect a bearing point to a lubricant source (indirectly from a meter or gang block, or directly from the pump) and allow the lubricant to be contained within the line to flow without constriction. As lube-delivery systems are hydraulic in nature, the line must also be capable of withstanding pressures ranging from hundreds to, in some cases, many thousand of pounds-per-square-inch (psi) of pressure.

Listen to the latest in a series of monthly lubrication-related podcasts with Ken Bannister. This edition of the podcast focuses on lubrication-delivery line matters.

Line size and material

Correct choice of size and material is essential if a lubricant-delivery line is to provide reliable service. For the most part, the line plays a passive role within a centralized system and is typically fixed to the side of a machine (the exception being where a lubricated part moves independently of a piece of fixed machinery, in which case, the line is used to provide the flexible connection.) Before a delivery line can be specified, however, a number of basic questions regarding the overall lube-system design must be answered, including:

Fig. 2. The bundled plastic tubing in this progressive-divider system are difficult to individually trace from pump to the lube block. These types of lubrication-delivery lines are also difficult to physically attach to a machine’s frame and, consequently, more vulnerable to damage.

Fig. 2.
The bundled plastic tubing in this progressive-divider system are difficult to individually trace from pump to the lube block. These types of lubrication-delivery lines are also difficult to physically attach to a machine’s frame and, consequently, more vulnerable to damage.

Is this system automated or manual? The answer is crucial in assessing line material, diameter, and wall thickness, which relate specifically to the line’s material-burst pressure rating.

• Manual systems designed to “gang” grease nipples in a central block can be lubricated by grease guns capable of developing as much as 15,000 psi.

• Manual hand pumps and automated systems operate at much lower pressures (between 100 and 2,000 psi).

What type of automated/engineered delivery system is specified? Some system designs require a single line size throughout, whereas others require a main and secondary line of different diameters and flow rates. For example:

• Single-line-resistance and pump-to-point systems are low-pressure systems designed to deliver the total amount of lubricant in one pump cycle. In such systems, i.e., total-loss, single-size-diameter delivery lines are sufficient.

• Single-line positive-displacement-injector, dual-line-injector, and progressive-divider systems require multiple cycles of the pump connected to a larger diameter main line used to rapidly fill the injectors/main distribution blocks, and smaller-diameter secondary lines that connect the metering outlets to the lubrication points,

• Re-circulating-oil systems usually require single-size-diameter delivery lines and a larger-diameter, return-line system.   

How many lubrication points are included in the system and where are they located on the machine? This question is required to map out a central pump location and injector or delivery block locations so the line distances can be measured for material take-off amounts, and in the case of long line lengths, to calculate pressure drop so the correct line diameter(s) can be calculated.

What lubricant type and grade/viscosity are you planning to use? The fact that grease requires higher pressure than oil to move through blocks and lines will affect the choice of line material type and diameter.

Fig. 3. If single-chamfered compression fittings designed for nylon lines are mistakenly used on steel lubrication-delivery lines that require double-chamfered fittings, seals can be compromised, causing leaks at the fittings. (Courtesy Bijur Delimon International, Morrisville, NC, bijurdelimon.com.)

Fig. 3. If single-chamfered compression fittings designed for nylon lines are mistakenly used on steel lubrication-delivery lines that require double-chamfered fittings, seals can be compromised, causing leaks at the fittings. (Courtesy Bijur Delimon International, Morrisville, NC, bijurdelimon.com.)

In what type of working environment will the system be used? Ambient and working temperatures can affect line integrity. Furthermore, if unprotected, copper, brass, and plastic lines can be easily damaged in high traffic areas—especially where lift trucks are used regularly.

What is your budget? Cost should not be a factor in line choice. Figures 1 and 2 show progressive-divider blocks, one piped in correctly rated plastic tubing and the other in steel. While steel tubing (Fig. 1) takes considerably longer to install, the additional, but small, up-front cost can pay long-term dividends, especially when a problem, such as a leak or a blocked line, occurs. The plastic tubing (Fig. 2) is bundled together. making it difficult to individually trace a line from the pump to the lube block. In addition, these lines are difficult to physically attach to the machine frame and, consequently, more vulnerable to damage.

Although the steel lines used in Fig. 1 are dirty, they all have line-ID (identification) tags that make them easy to trace and troubleshoot. The steel-line system also looks more engineered and permanent in comparison with the bundled-plastic-line example.

Once you’ve gone through these six questions, present the answers to your lube-system designer or manufacturer/supplier. These resources can help you determine the best line material for a specific application.

Main problem causes

Problems in lubrication-delivery lines manifest as leaks or blockages. A leaking line will starve lubricant from one or many bearing points and seriously affect the associated production equipment’s reliability. Leaks are invariably found at connection points and line-bend areas. Keep the following in mind:

• Copper lines are very soft and can easily work-harden at bend points if significant machine vibration occurs.

• Nylon lines can be easily over-tightened or not cut square at the connection points. This can cause a leak at the compression fitting.

• If a single-chamfered compression fitting designed for nylon lines is mistakenly used on a steel line, which require a double-chamfered compression fittings (see Fig. 3), they can be compromised, causing a leak at the fitting.

• To reduce cost, nylon lines can be used as a substitute for flexible-hose lines in moving-bearing-point applications found on, among other things, machine slides and rams. Plastic lines, in most cases, are not rated for cyclic repetitive-movement duty.

Blockages in lubrication lines usually occur when they’re pinch-damaged from being hit by a foreign object that crimps or flattens the line shut. This situation causes a line backpressure that can blow the fitting or eventually stall an entire progressive-divider system, starving many bearings in the process. Steel lines offer the best defense against pinched lines.

Best practices

To ensure no bearing is starved after a lubrication-system implementation or line replacement, always pre-fill the lubricant line with the correct grease lubricant before final fastening to the bearing. Or, in the case of oil, operate the lube system and open all bearing points to ensure oil is flowing at each point before final tightening.

Finally, never forget that lubrication-delivery lines are a matter of choice. Reliable lube systems, in turn, depend on making the correct choice. MT

Contributing editor Ken Bannister is co-author, with Heinz Bloch, of the book Practical Lubrication for Industrial Facilities, 3rd Edition (The Fairmont Press, Lilburn, GA). As managing partner and principal consultant for Engtech Industries Inc. (Innerkip, Ontario), he specializes in the implementation of lubrication-effectiveness reviews to ISO 55001 standards, asset-management systems, and training. Contact him at kbannister@engtechindustries.com, or telephone 519-469-9173.

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